Explosion prevention control for dry-cleaning machines



Oct 1943. w. F. GAYRING 2,333,000

EXPLOSION PREVENTION CONTROL FOR DRY CLEANING MACHINES Filed May 20, 1942 s Sheets-Sheet 1 INVENTOR. WALLACE F. GAYRING 4 @MMd W ATTORNEYS Ot..26,1943. w. F.4GAYRING 0 2,333,000

I EXPLOSION PREVENTION CONTROL FOR DRY CLEANING MACHINES Filed May 20, 1942 3 Sheets-Sheet 2 5 mm sw. 34 43 J 59 40* I A 1; Lr\ rT V 4- ll l n I u H in 3? 5 4B 4| 46 /59 i l I I r I 59 a i 1 28 WALLACE E GAYRING Oct. 26, 1943. w. F. GAYRING EXPLOSION PREVENTION CONTROL FOR DRY CLEANING MACHINES 3 Sheets-Sheet 3 Filed llay 20, 1942 m n mu N- 0 mm a M an? ATTORN EYS device.

Patented Oct. 26, 1943 UNITED STATES PATENT OFFICE,

EXPLOSION PREVENTION CONTROL FOR DRY-CLEANIN G MACBIN ES Wallace r. Gayring, Minoa, .N. Y., asslgnor to The Prosperity Company, Inc., Syracuse, N. Y., a corporation of New York' Application my 20,1942, Serial No. 443,151

3 Claims.

This invention relates to machines for removing the residual solvent from articles alter being dry cleaned and the solvent for the most part removed, as by a centrifugal extractor. In

removing the residual solvent and de-odorizing such articles, heated air is passed through the articles, while in the machine, to vaporize the residual solvent, while the articles are being agitated in the machine. Such a machine is the proportion of air to the vapor increases, the

concentration point is not readily reached. Hence, air at a higher temperature than the flash point may be used to facilitate the removal .of the residual vapor and the de-odorizing of the article. The invention has for its object means for controlling the temperature of the air passing into the machine in accordance with the explosive concentration point of the mixture, or

specifically by a device sensitive'to an explosive mixture, which, when. the vapor approaches explosive concentration at any time in the operation, immediately lowers the temperature of the incoming air, to below thepoint of danger of explosion, or means tor automatically controlling the heating and cooling or the air by a device sensitive to the explosive vapor in the air stream.

'I'hev invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

, In describing this invention, reference is had to the' accompanying drawings in which like characters designate-corresponding parts in all the views. I Figure 1 is a vertical sectional view or a dry ing machine embodying this invention. 7

Figure 2 is a diatic view illustrating the control of the air by the explosive sensitive Figure 3 is a tic view similar to Figs are 2 of, a slightly modified form of the invention.

Figure 4 is a sectional view of one form or device sensitive to an explosive mixture.

Figure 5 is a sectional view of the said device as used in the arrangement shown in Figure 3.

l designates the drying tumbler including an outer casing having a perforated drum 2 therein mounted to move or oscillate about a'horizontal axis in the casing, it being shown as mounted upon a shaft 3 journalled in any suitable manner in the casing. The outer casing and 5 the drum 2 have doors 4, 5, respectively, for loading and unloading the articles, it being necessary to move the drum into such radial position that the door 5 is alined with the door 4 when loading and unloading. The casing is provided with an inlet 6 at its upper portion for air, and with a contracted outlet 1 at its lower end, the air passing through the perforations of the dl'lmi and through the articles or clothes C therein and out through the outlet 1, while the drum 2 is being oscillated totumble the clothes. ,The

machine and parts pertinent thereto, to be described, are enclosed in a suitable cabinet 8.

The means for heating the incoming air may be of any suitable construction, and as here shown, two heat exchangers 9, III are provided in the upper portion of the' cabinet, these opening at their outer ends at H and I! to the outer air and. opening at their inner ends into a" chamber l3 at the top of the cabinet which communicates with the air inlet 6 of the casing l-.- The heat exchangers 9, It may be of any suitable construction, and as here illustrated includes suitable heating elements, here shown as steam coils I4, i5 respectively. The flow of steam through the coils l4, i5 is controlled by valves I6, II respectively. .These valves are controlled in their operation by devices sensitive to an explosive mixture to be presently described, and also the flow of air through the heat exchanger III is controlled by a damper or closure I8 also controlled by said device. One of the valves, as It, is initially controlled by a thermostat is arranged in the chamber l3 to partly open the steam valve ii to maintain a temperature when the machine is in operation at a point below mixture of air and solvent is caused to pass out the casing I, as through the contracted outlet I by means including a blower 20, the inlet side of which is connected to the outlet 1 of the casing i, and the discharge side oi which communicates with a suitable outlet pipe 22. The rotor 23 of the blower-is'actuated by a suitable electric motor 24. Also, the drum 2 is actuated by a suitable electric motor 25.

The temperature of the air passing into the casing l iscontrolled by mixture sensitive device 26 havingv an intake arranged to receive the mixture, preferably as near as possible to the outlet 1, said device controlling the opening and closing of the steam valves l6, l1 and co the damper It. The valves I6, l1 and also the damper I8 are operated by compressed air motors or instrumentalities controlled by the mixture sensitive device.

The mixture sensitive device operates on the principle of explosion meters and the specific construction thereof forms no part 01 this invention. It is arranged so that portions or samples of the vapor are being continuously forced through it by the draft created by the blower 20. The device here shown is fully described in Patent Number 1,779,569 issued October 28, 1940. When there is an explosive concentration passing through the device 26, it operates to open a normally closed switch 28 including mercury located in the bend of a U-shaped tube 29 and normally bridging two contacts 30, iii in an electric circuit in the embodiment of the invention shown in Figures 1, 2 and 4. When there is an explosive concentration in the device, the column of mercury is'shifted out of contact with one of the contacts 30, so that the circuit controlled by the mixture sensitive device is opened. Thus, when there is no explosive concentration passing'through the device, the circuit controlled by the switch 28 is closed. When the switch 218 is closed, the heat generated in the mixture sensitive device and the tube 29 opens the switch 28. This switch is located in a circuit including electro-responsive devices, which operate the steam valves, causing the steam valves to close and permit cold air or air in this instance not above 130 to pass into the casing i and the tumbler. The purpose oi'the damper i8 is to close the heat exchanger Hi to the passage of air therethrough over the steam coils it, which remain hot for a period after the steam valve I1 is closed, so that when the damper i8 is closed, even though the steam coils is are hot, the air is not being circulated over the coils by the blower 20. Thus, when the damper id is closed, the casing of the heat exchanger it is closed to the inlet of air, and hence the air passing into the tumbler is heated only by the air passing through the heat exchanger 9, the steam valve of which is closed, except that it may be partly open under the influence of the thermostat IS. The thermostat is merely acts, when heated, to expand the mid through pipe li connecting the end of the diaphragm chamber lo with suiflcient pressure to partly open the valve I! when the diaphragm chamber 33 is not energized.

The air operated mechanism for operating the valves l8, l1 and the damper II will now be described.

The steam valves ll and I? are operated by air pressure to open position, and the means for operating them comprises diaphragm chambers 33, 34, one for each, the movement of the diaphragm in the chamber transferring the inction to the movable member or the valve It or II through suitable fmotlon transmitting means including a rod ll movable in a guide 3! and connected to the movable member 01 thevalve. The pressure side of the diaphragm chamber 33 for the valve I0 is connected by a conduit 81 to the casing 3| of a combined intake and exhaust valve, the casing being connected to a supply pipe as. The pressure side oi the-diaphragm chamber 34 for the steam valve I1 is connected by a conduit llv to the casing ll of a combined intakeand exhaust valve, this casing being connected to the supply pipe 38. The damper l8 is also operated by 'a diaphragm in a similar diaphragm chamber 42, the. pressure side of which is connected by a pipe 48 to the casing ll mally open, exhaust valve head 610, these being connected so that they act as a unit. When the members in the casing 38 and ii are operated to open the intake head and close the exhaust head, air passes from the main line t9 through the valve 38 and pipe 8? to the diaphragm chamber 33 to open wide the steam valve it and through the valve ti, pipe (it to diaphragm chamber 34 for the steam valve l1, and pipe 43 to diaphragm chamber 32 to open the damper it.

The valves are electrically operated by electro-responsive devices, as solenoids il, 68, the core of which is connected to the movable member of the valve 88 or iii.

' The motor 26 is connected in feed wires 59 and Bi as follows: Through wire 52 and return wire 53. The motor 25 is connected in the feed circuit'through wires 52, Fit and return wire 55. The windings of the solenoid 31 are also connected in the feed circuit through wire 52, wire 56, and return wire 51 to the other feed wire 5!. The windings of the solenoid as, which con-,

trols the steam valve l7 and damper it, are concontact at of the switch 28 of the mixture sensitive device to the windings of the solenoid id, wire to to return wire 51. Suitable control switches S-W are located in series in the feed line, one operated by hand, and the other by the door 5 of the casing i.

The valve it is opened by the operation of the solenoid ll, the windings of which are connected directly in the feed circuit through wires 58, 61 so that when the feed circuit is closed By the switches SW, the solenoid M is immediately energized and the valve it opened.

. closed, and the heating of the air passing through At the start, the switch 28 of the mixture sensitive device is normally closed. The vapor from the clothes, when first placed in the drum 2, is usually at or above the concentration point. The opening of valve I6 is controlled by the action of the thermostat It to heat the air up to that is, up to a point below the flash point of the vapor from the solvent, this being about Upon the closing of the door, the motors 24, 2 5 are energized, and hence, as the blower 23 is now in "operation, the vapor is drawn from the casing i through the outlet I and a part or sample 01' it forced continuously through the mixture sensitive device. As this vapor is near, at or above the concentration point. the switch 28 of the mixture sensitive device is opened, and hence the circuit through the solenoid ll broken, and the valve I7 and damper II the casing i is the heat generated in the 130 heat exchanger 8 only. When both switches B-'-W are closed, upon the closing of the door,

the solenoid 41 is immediately energized-permitting compressed airto flow to the diaphragm chamber 33, so that the valve II is now open, but the extent to which it is opened is blockedby the thermostat l8, which limits the opening of the valve, and hence the temperature to 130 or below the flash point of the solvent vapor, which, say is 140. Thus, while the solvent vapor passing through the mixture sensitive device is at or above the concentration point, the temperature is held by the thermostat to below the flashpoint. During continued operation, and asthe solvent falls below the concentration point, the

switch 2! or the mixture sensitive device closes,'

and hence establishes a circuit throush solenoid 48 and the valve 4| opened topermit air to-flow to the diaphragm chambers 34 and i2 and open the steam valve II of the'heat exchanger ill and open the damper I! to permitto pass t us e "A. Hence. while the concentration the explosive.

the drop in temperature is eflected by letting cold air into the cabinet I or the chamber I4 thereof immediately when the explosive concentration point is approached or reached. In this form of the invention, the switch I" of the mixture sensitive device 264 is normally open instead of being normally closed, and the cabinet I is provided with an air inlet 05 opening directly into the cabinet 8 or the chamber l4 thereof. The

inlet 85 is normally closed by a damper orclosure iii. The damper is opened by the closing of the switch280 of the mixture sensitive device, this closing when an explosive concentration is being approached or reached. The damper 66, when operated from its normal or closed position to open the inlet 65, thus renders ineffective the heat exchanger 18 by by-psssing said-heat exchanger, so that the air circulated comes in from outside of the casing instead of passing through the heat exchanger Also, the damper 66, when operated out of its normal position closes, as indicated in dotted lines in Figure 3, the heat exchanger, so that air ,from the heat exchanger does not mix with the colder air coming in through the inlet. The damper is here shown as opened by a pressure fluid motor controlled by an electro-responsive device or solenoid 8 1 similar to the solenoids 41 and 48 and operating a valve is similar to the valves is and 4|. When the switch 2 oi. the mixture sensitive device is closed, the solenoid 01 is energized, thus opening the valve to the intake of air from the reed pipe, as as, through pipe as to a pressure operated motor, which acts to open the closure 86. This motor is here shown as a cylinder I. having' a piston ll therein, the stem 12 or which is connected by a link "to an angular crank arm 14 on the closure 88. The motion of the piston II. is against a returning spring Il. Thus, when the switch 280 of the mixture sensitive device closes, as it does in this instance, when an explosive concentration is reached, the circuit through the solenoid 81 is closed, and hence a" pressure fluid,

- as air,,flows to the cylinder ll, actuates the piston II, to open the closure I and immediately lets a large quantity of cold air in to the cabinet I to reduce the temperature below the flash point of vapor. Figure3,theairisbeingheatedbyaheatexchanger It with no automatic control and the a 70 In this construction shown inair passing through the air inlet 65, when the closure 66 is open, is of such volume as to immediately'reduce the temperature of the air heated by the heat exchanger II to below the flash point. 5 In either form of the-invention, the operation is automatically controlled and the temperature of the air and the vapor kept below the flash point of the vapor, when an explosive concentration is being approached and the temperature permitted to rise above the flash point when the concentration .is below an explosive concentration. As the control is entirely automatic, the removal of residual solvent from the clothes and deodorizing of the clothes is greatly facilitated, or this operation performed in a relatively short time.

What I claim is:

i. In a drying machine for removing from articles residual solvent which vaporizes and forms an explosive mixture with air, said machine including a casing having an air inlet and an outlet through which the vapors are passed, means for heating'the air passing through the inlet, means for passing the mixture of air and vaporized solvent through the outlet, a device sensitive to the chemical re-action between-the solvent vapor and the air and arranged to continuously receive samples. of the mixture from the outlet, and means rendered operative as a result 0 of said chemical action, between the solvent vapors and the air passing through said device, I

to render the heating means ineffective to heat the air passing through the inlet, when the mixture is approaching an explosive concentration.

articles residual solvent which vaporizes and forms an explosive mixture with air, said machine including. casing having an air inlet and an outlet through which the vapors are passed, means for heating the air passing through the inlet, means for passing the mixture of air and vapor- .ized solvent through the outlet, a device sensitive to the chemical re-action between the solvent vapor and the air and arranged to continuously receive samples of the mixture from the outlet, and means rendered operative as a result of said chemical action between the solvent vapors and the air passing through said device, to shut 011 ing an explosive concentration.

3. In a drying machine for removing from articles residual solvent which vaporizes and forms anexplosive mixture with air, said machine 5 including a casing having an air inlet and an outlet through which the vapors are passed,

means for heating the air passing through the inlet, means for passing the mixture or air and vaporized solvent through the outlet, a device sensitive to the chemical re-sction, between the the outlet, a second air inlet of outer air, a closure normally closing the second inlet, and means operative as a resultoi said chemical re-action between the solvent vaporsand the air passing throushsaiddevicatoopensaid closuretothe second inlet of outer air and thus cut out the heating means .byby-passing the air away from proaching an explosive concentration; I

WAILACE I". GAYRD' IG.

2. In a drying machine i'or' removing from the heating means when the mixture is approachsolvent vapor and the air and arranged to continuously receive samples of the mixture from" the heating means, when the mixture is -aD 

